Thermally insulated tank structure

ABSTRACT

AN INSULATED TANK STRUCTURE COMPRISING A PLURALITY OF PANELS HAVING AN INSULATING MATERIAL SECURED THERETO WHICH ARE ARRANGED ABOUT THE OUTSIDE WALLS OF A TANK STRUCTURE AND CAUSED TO RETAIN ITS POSITION THEREON BY MEANS OF A NOVEL SECURING MEANS WHICH WILL PERMIT FOR THE EXPANSION AND CONTRACTION OF THE SECURING MEANS AND PANELS SECURED THEREBY DUE TO TEMPERATURE CHANGES OCCURRING WITHIN THE TANK STRUCTURE.

A ril 11, 1972 E. e. MARCMANN Re. 27,330

THERMAL-LY INSULATED TANK STRUCTURE 8 Sheets-Sheet 1 Original FiledApril 12, 1968 INVENTOR EMIL MARCMANN April 1972 E. G. MARCMANN Re.27,330

I THERMALLY INSULATED TANK STRUCTURE Original Filed April 12, 1968 8Sheets-Sheet 2 EMIL April 11, 1972 E. e. MARCMANN Re. 27,330

THERMALLY INSULATED TANK STRUCTURE Original Filed April 12, 1968 8Sheets-Sheet 3 EM 1; MARCMANN ATTORNEY April 11, 1972 E. G. MARCMANN Re.27,330

THERMALLY INSULATED TANK STRUCTURE 8 Sheets-Sheet 4 Original Filed April12, 1968 Y N Wm M m a m A M H M w E w M .n I m. K

A ril 11, 1972 G. MARCMANN Re. 27,330

THERMALLY INSULATED TANK STRUCTURE 8 Sheets-Sheet 5 Original Filed April12, 1968 INVENTUR EMIL M ARCMANN AT TOR N EY April 11, 1972 s. MARCMANNRe. 27,330

THERMALLY INSULATED TANK STRUCTURE Original Filed April 12, 1968 8Sheets-Sheet 6 INVENTOR EMIL MARCMANN ATTORNEY April 1972 E- G. MARCMANNRe. 27,330

THERMALLY INSULATED TANK STRUCTURE Original Filed April 12, 1968 8Sheets-Sheet 7 INVENTOR EMIL MARCMANN 1 BY v KK /L' ATTORNEY April 11,1972 E. G. MARCMANN Re. 27,330

THERMALLY INSULATED TANK STRUCTURE Original Filed April 12, 1968 8Sheets-Sheet 8 T 15 62 k 15: i: M t 5 \63 U 4 62 i r r- T ray J m r Fmvcmon EMIL M AQCMANN AT'TO RN EY United States Patent 27,330 THERMALLYINSULATED TANK STRUCTURE Emil G. Marcmann, Medford, NJ. 08055 OriginalNo. 3,456,835, dated July 22, 1969, Ser. No.

720,943, Apr. 12, 1968. Application for reissue June 3, 1970, Ser. No.43,247

Int. Cl. B65d 25/18 US. Cl. 2209 F 10 Claims Matter enclosed in heavybrackets [1] appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE An insulated tank structure comprising aplurality of panels having an insulating material secured thereto whichare arranged about the outside walls of a tank structure and caused toretain its position thereon by means of a novel securing means whichwill permit for the expansion and contraction of the securing means andpanels secured thereby due to temperature changes occurring within thetank structure.

BACKGROUND OF THE INVENTION In the petroleum and chemical industries itis customary to store liquids and the like within large tank structureswhich are usually installed out in the open where they are exposed tothe elements, both heat and/or cold. These storage facilities usuallycomprise circular steel or other metallic tank structures which, byreason of being installed out in the open, must be provided with asuitable insulating material so that the products in storage within thestorage tanks may be kept at the desired temperatures. In previousstorage tank insulation, it has been customary to apply some type of aninsulating material exteriorly of the metallic tank structure and tosecurely bind the same thereto by the use of an adhesive or bycircumferential bands extending completely around the outside diameterof the tank and secured in a fixed position. The manner of securinginsulating panels to the exterior of a metallic storage tank isobjectionable for the reason that the tank structure is oftentimesexposed to varying temperature gradients with the result that themetallic shell is caused to expand and contract due to such temperaturevariations. Obviously, if an insulating material has been applied to theexterior surface of such a tank as by adhesively securing the samethereto, the adhesive bond between the metallic shell and insulatingmaterial is caused to be broken due to such expansion and contractionwith the result that the insulating material is separated from themetallic shell with resultant loss of insulation for the tank at suchspots or areas. In instances Where the insulating material is secured tothe tank structure as by means of exteriorly extending citcurnferentialbands, the bands are usually set to a pretensioned force at the time ofinstallation of the insulating material and when, by reason of difleringtemperature gradients, the tank walls are caused to expand and/orcontract, the bands, which are usually formed of metal are incapable offurther stretching to accommodate the expansion of the tank andinsulating material thereon and will break or snap ofi' thusnecessitating the repair or replacement of such bands. On the otherhand, where the tank structure is caused to contract, the metallic bandslose their efficiency as holding means for the insulating material sincethe bands are not exposed to the temperatures within the tank whichcauses such contractron of the metallic tank.

In recent years, attempts have been made to insulate the exterior ofstorage tanks by using various type foamed resinous materials but, hereagain, difficulties have been encountered in properly maintaining suchinsulating material on a structure to be insulated.

Also, various means have been employed for securing a foamed backedpanel to the exterior surface of a storage tank but such securing meansdid not allow for the expansion and contraction of the storage tank byreason of the tank being exposed to varying temperature gradients withthe result that such insulating material has not proven to be entirelysatisfactory. The previous attempts to insulate a storage tank with afoamed insulating material encountered considerable difficulties as noprovision was provided for the creeping or expansion of the foamedinsulating material and quite frequently the foamed material tended tobuckle or otherwise deform the sheet supporting the same on the exteriorof the tank thus necessitating the replacement of the insulatingmaterial.

With the above in mind, it is therefore the main object of the inventionto utilize a foamed plastic material as the insulating material and tosecure the same in any manner, as by adhesive and the like, to a backingsheet usually composed of a thin aluminum sheeting, and to securelyfasten the same about the outer walls of a tank to be insulated by strapelements which will permit for the ready expansion and contraction ofthe tank structure while eflectively maintaining the insulating materialin face to face relation with the tank walls.

Another object of the invention is to provide for a novel support meanswhich is adapted to be arranged in staggered vertical position on theexterior of the wall of the storage tank to be insulated and which willoverlie the adjacent edges of sheeting having the insulation materialbonded thereto so as to prevent the entry of rain water and the likebetween the support and sheeting.

Another object of the invention is to provide slots at opposite ends ofthe supports extending vertically between the sheeting so as to form aninterlock between the top and bottom edges of each adjacent sheeting asWell as to accommodate the top and bottom edges of the circumferentialband which encircles the tank for retaining the sheeting in properposition thereon.

Another object of the present invention is to provide a novel means forsecuring the ends of a circumferentially extending band about a tankstructure which will permit for the expansion and contraction of thetank structure while still eifectively maintaining the insulatingmaterial in close contact with the exterior walls of the tank beinginsulated.

Still another object of the invention is to provide for a simplifiedmanner of maintaining the insulating panels in close proximity to theexterior walls of a tank to be insulated to thus provide the workmenapplying the insulating sheeting with a means for supporting aninsulating sheet in proper position prior to securing the same to atank.

Other objects and advantages of the invention will be pointed outspecifically or will become apparent from the following description whenit is considered in conjunction with the appended claims and theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side elevationillustrating an embodiment of the invention in the form of an insulatedstorage tank of generally cylindrical configuration disposed in avertical position.

FIGURE 2 is an enlarged fragmentary elevational view of a portion of theinsulating panels shown in FIG. 1 and also showing the clamp securingmeans.

FIGURE 3 is a horizontal sectional view taken along the lines 3-3 ofFIG. 1, looking in the direction of the arrows.

FIGURE 4 is an enlarged detailed fragmentary sectional view of a portionof FIG. 3.

FIGURE 5 is a view similar to FIG. 4 and shows the insulating media inan expanded condition.

FIGURE 6 is a detailed vertical sectional view taken on the line 66 ofFIGURE 4, looking in the direction of the arrows with parts broken away.

FIGURE 7 is a sectional view similar to FIGURE 6 showing in full linesthe parts broken away in FIGURE 6.

FIGURE 8 is a perspective view of one of the vertical support elements.

FIGURE 9 is an enlarged detailed fragmentary sectional view of amodified form of the vertical support elements.

FIGURE 10 is a detailed vertical sectional view taken along the lines1010 of FIGURE 9 looking in the direction of the arrows.

FIGURE 11 is an enlarged fragmentary sectional view taken along the line11--11 of FIGURE 1 showing the structure for sealing the insulatingpanels adjacent the tank roof.

FIGURE 12 is a horizontal vertical fragmentary sectional view takenalong the line 12-12 of FIGURE 11, looking in the direction of thearrows.

FIGURE 13 is an elevational view of the preferred form of band securingand tensioning means.

FIGURE 14 is a horizontal sectional view taken along the line 14-14 ofFIGURE 13, looking in the direction of the arrows.

FIGURE 15 is an enlarged detailed vertical sectional view taken alongthe line 1515 of FIGURE 14, looking in the direction of the arrows.

FIGURE 16 is an elevational view of a modified form of a band securingand tensioning means.

FIGURE 17 is a horizontal detailed sectional view taken along the line1717 of FIGURE 16.

FIGURE 18 is a side elevational view of a work holder employed duringinstallation of the insulating panels.

FIGURE 19 is a front elevational view of the work holder shown in FIGURE18.

FIGURE 20 is a perspective view of one of the insulating panels employedwith the present invention, and FIGURE 2.1 is a top plan view of theinsulating panel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings,there is shown at FIGURE 1 thereof a storage tank which is usually inthe nature of a tank of about 60 feet in diameter and about 90 feethigh. The storage tank is normally set on a concrete base showngenerally at 10 and it is pointed out that the tank size set forth aboveis given as an example of size only and the invention shown herein, ofcourse, is not to be limited to any size tank or any particular tankconstruction. The storage tank shown in FIGURE 1 is usually constructedof a number of prefabricated metallic panels suitably secured to oneanother to form a completed enclosure. Tanks of this general nature arenormally employed for the storage of liquids for subsequentredistribution. While in storage the liquids within the tank aremaintained within given temperature ranges depending upon the nature ofthe liquids being stored and such tanks are usually provided interiorlythereof with heating or cooling means for maintaining the stored liquidswithin the desired temperature ranges. As can be appreciated, such tanksmust of necessity be provided with an exterior layer of insulatingmaterial so as to minimize any heat loss.

Again referring to FIGURE 1, there is shown therein a plurality ofinsulating panels 11, vertical supports 12, and circumferential bands13. The vertical supports 12 preferably are formed of extruded aluminumand are in the nature of a modified T shape as shown more clearly atFIGURES 4, 5 and 8 of the drawings .While I have described such supportsas being formed of extruded aluminum it is obvious such supports may beconstructed of other metallic or plastic substances. The panels 11 areof a generally rectangular shape and comprise an outside sheet or facing14 formed of aluminum, galvanized iron, or any other suitable material.A preformed sheet of an insulating material, preferably foamed plasticis adhesively or otherwise secured to one face of the panel 11 and isadapted to be disposed in face to face relationship with the outsidewall 15 of the tank structure.

It has been found advantageous and economical to prepare the insulatingpanels from metallic panels cut to the desired size and applying anadhesive material on one side thereof and thereafter applying a sheet ofplastic foam of the desired size to the panel and passing the laminatebetween a series of rollers which will press the laminate into tightengagement with one another, and, if the lamniate is to be preformed toa given curvature so as to follow the contour of the tank to which it isto be applied, the roller structure can be set to impart the desiredcurvature to the laminate while simultaneously pressing the foamedmaterial thereagainst.

As can be seen more clearly at FIGURES 20 and 21 of the drawings, thepanel 11 is generally rectangular in shape and when the foamed plasticsheet is laminated thereto, the upper edge of the foamed plastic 16 isflush with the top edge 17 of the outside sheet or facing 14 whereas thebottom 18 and side edges 19 of the foamed plastic terminate short of thebottom and side edges of the outside sheet or facing 14 for a purpose tobe more fully described hereinafter.

Referring now to FIGURE 8 of the drawings, there is shown therein one ofthe vertical members or supports 12 which are adapted to be arrangedbetween the side edges 19 of next adjoining panels 11. The supports 12are designed to be arranged in staggered relationship as shown in FIGURE1 of the drawings and comprise a generally T-shaped extrusion havingflanges 20 and 21 extending outwardly from the center piece 22 of thesupport. Formed intermediate the centerpiece 22 are a pair ofprojections 23 and 24 which are preferably formed integral with thecenterpiece 22. As can be seen, both the flanges 20 and 21 andprojections 23 and 24 extend the full length of the vertical support 12and as best seen in FIGURE 8 of the drawings, clots 25 and 26 are formedat the upper and lower ends of the supports for a purpose to be morefully described hereinafter.

As can be appreciated, the panels 11 are arranged about the outer wall15 of the tank structure and are so positioned thereabout so as tostagger the meeting edges of the panels and thus likewise stagger theposition of the vertical supports as shown in FIGURE 1 of the drawings.

Referring now to FIGURE 7 of the drawings, there is shown therein themanner in which an overlapping arrangement is provided between thebottom edge 17' of one panel and the upper edge 17 of the nextsucceeding panel. As set forth previously, particularly with respect toFIGURES 20 and 2], the plastic foam does not extend to the edge of theoutside sheet or facing 14 which permits for the overlapping of thatportion of the facing with the top edge 17 of the next succeeding panel.Thus, it wil be seen that as the panels are arranged exteriorly of atank structure, the top edge 17 of the lowermost panel wil be overlappedby the bottom edge 17' of the next adjacent panel and when thusassembled, the plastic foam sheets 16 abut one another therebycompletely covering the outside wall 15 at the juncture between the topand bottom edges of adjacent panels. Again, referring to FIGURE 7 of thedrawings, it will be seen that the lower edge 17' of sheet 14 extendswithin the slot 25 formed in the upper end of the support 12 to enablethe upper and lower edges of the panels to overlap and to thus providefor a connection between adjacent panels which will exclude rain or anyother extraneous matter from between the panels and likewise from intothe foamed plastic. Once the panels have been joined in overlappedrelation, as set forth above, a circumferential band 13 is caused toextend within the slots 25 and 26 and following the application of a rowof panels about the exterior of the tank structure, in the manneraforesaid, the band ends are then caused to be fastened to a suitablefastener means in a manner to be described more fully hereinafter.

Referring now to FIGURES 4 and of the drawings, there is shown thereinthe side edge connection of adjacent panels. As clearly shown, support12 is adapted to be disposed between the lateral side edges of theadjacent panels with the flanges 20 and 21 overlapping the side edges19'. Obviously, this type of connection insures the exclusion ofextraneous matter from the foamed plastic. The foamed plastic sheet 16terminates short of the side edges 19 of the outside sheet or facing 14as clearly shown in FIGURES 20 and 21. Prior to installation of thepanels to the exterior wall of a storage tank, the foamed plastic sheetwhich has been adhesively or otherwise secured to the facing or sheet14, terminates short of the side edges 19 for a reason to be more fullydescribed hereinafter.

FIGURE 4 of the drawings discloses the relative positions of thevertical support 12 and the adjacent edges of the foamed plastic sheets16 when the insulating sheets are intially applied to the exterior wallof a tank to be insulated. The plastic foamed sheet is shown to extendwell within the side edges 19' of the outside sheet 14 so as to allowfor the plastic foamed sheet to creep or expand when it has beensubjected to the high temperatures maintained within the storage tank.Shown at FIGURE 5 are the adjacent side edges of the sheets of foamedplastic material which has expanded after the same has been exposed toelevated temperatures. It will be noted that the foamed plastic sheetshave engaged with the projections 23 and 24, embedding the same withinthe foamed plastic sheets so as to further stabilize the verti calsupports 12 in their assembly with the other components employed hereinfor erecting an insulating medium about the exterior surface of astorage tank. Thus it will be seen that provision is hereby made for theexpansion of the foamed plastic material without causing any unduestresses on the sheeting 14 and without disturbing the placement of thevertical supports 12.

FIGURES 9 and of the drawings disclose a modified form of the verticalsupports 12 employed in erecting the insulation panels constructed inthe manner previously described. This modification of the support isdesigned to be employed and to function in the same manner as previouslydescribed except that in this modification, a pair of lips 27 and 28 areformed integral with the support 12 and are adapted to cooperate with apair of inturned cars 29 and 30 to house therebetween the opposite edgesof the facing 14 thereby preventing separation of the support 12 fromthe facing 14 thus insuring the non-entry of rain water or any otherextraneous matter within this connection between the panels. Asdescribed with reference to FIGURE 4 of the drawings, provision is madefor the creeping or expansion of the foamed plastic sheet when subjectedto elevated temperatures from within the storage tank.

Referring now more particularly to FIGURE 10 of the drawings, the sameshows the supports 12 having slots 25 and 26 formed at the upper andlower edges thereof which are adapted to receive therein the overlappingedge of the next upper adjacent insulating sheet and the circumferentialband 13 in the same manner and for the same purpose as has beendescribed with respect to FIGURE 7 of the drawings.

FIGURES 11 and 12 disclose the manner of excluding rain water and/or anyother extraneous matter from the foamed plastic material in contact withthe exterior wall of a storage tank. Shown at FIGURE 11 is a typicalslanted roof type storage tank with the walls of the tank securedthereto in any known manner. The foamed plastic sheet 16 and outsidesheet or facing 14 terminate short of the upper edge of the tankstructure. A plate 31 is secured as by welding and the like to theexterior wall 15 of the tank and extends completely around the tank. Thelower edge 32 of the plate 31 extends over the top edge 17 of facing 14.A circumferential band 33 similar to band 13 prviously described may beemployed for retaining the lower edge 32 of plate 31 in tight engagementwith the facing 14.

FIGURES l3, l4 and 15 disclose one form of a clamp which is designed tosecure the ends of the bands 13 after the same have been applied to theexterior of the insulating panels in the manner aforesaid. The clampcomprises a pair of like formed clamping members 34 and 35, eachcomprising a base member 36 and 37 having pairs of upstanding ears 38,39, 40 and 41. Mounted between ears 38 and 39 and 40 and 41 are tubularmembers 42 and 43. A pair of rods 44 and 45 extend through openingsformed in tubular members 42 and 43 and the outer ends thereof arethreaded to receive nuts 46, 47, 48 and 49. Springs 50, 51, 52 and 53are slidably mounted on rods 44 and 45 and washers 54, 55, 56 and 57 areinterposed between the springs and the tubular members 42 and 43. Thusit will be seen that the clamping members are capable of adjustment tolengthen or shorten the clamp by the mere manipulation of the aforesaidnuts on the aforementioned bolts. The ends of band 13 are secured to theclamping members by first threading the same through a sleeve-likemember 58 and thence to the forward edge of the clamp where the band isreversely bent and again threaded through the sleeve-like member 58.Following this, the loose end of the band can again be reversely bent asat 59 to complete the connection.

FIGURES l6 and 17 of the drawings disclose a modified type of clampingmember which can be employed for securing the band ends together. Inthis modification of the invention, a single rod 60 is employed in lieuof the pair of rods employed in the modification shown in FIGURES 13 and14 of the drawings. The clamp shown in FIGURES l6 and 17 is designed tooperate in the same manner as the clamp previously described except thatin this instance, instead of using a sleeve-like member through whichthe band ends are threaded, the band ends are merely wound about theclamp bases 36' and 37, as clearly shown in FIGURE 17.

Referring now to FIGURES l8 and 19, there is shown a vertical standard61 having a cross piece 62 secured thereto in any known manner. C-clamps63 and 64 are arranged on the cross piece 62 and rod engaging fingers 65are arranged at spaced intervals on the vertical support.

There will now be described the manner of erecting the insulating panelsto the exterior wall of a storage tank or the like. As can beappreciated, the panels are installed beginning with the lowermost rowof panels at ground level and continuing upwardly with such rows untilthe tank has been completely covered with the insulating panels. Oncethe first or lowermost row of panels has been placed about the tankstructure with the vertical supports placed between the side edges ofthe adjacent panels and with the panels in overlapped relation asdescribed previously, a circumferential band 13 is loosely mounted aboutthe tank and panels and engages in the slots formed in the upper andlower ends of the vertical supports. Following this, the next row ofpanels are mounted on top of the first row of panels with the bottomedges of the sheets disposed behind the loosely mounted band and lyingin overlapped relation with respect to the top edges of the precedingrow of panels. After this has been accomplished, the band ends aresecured to the clamping members and tension can then be applied to thebands by adjusting the clamping members in the manner describedhereinabove. After the first few rows of panels have been applied in themanner aforesaid, it then becomes necessary that some means be employedfor maintaining the band in a position where the same can be easilyhandled by the workmen installing the panels. For this purpose, I haveprovided the vertical standard With the cross piece and rod engagingfingers. As the installation progresses upwardly, the band ends may beengaged in clamps 63 and 64 and the band held at the desired elevationby engaging the clamping rods of the clamps with the rod engagingfingers on the vertical support. This manner of handling the band isrepeated as each row of panels is installed.

As can be appreciated, I have provided herein an improved means ofoverlapping next adjacent edges of insulating panels and likewise havedevised an improved vertical support which is mounted between the sidesedges of next adjacent insulating panels for effectively securing theassembly including the circumferential band which extends between eachrow of panels and overlies the overlapped panel edges.

Also, it should be pointed out that the improved means of securing theband ends together is one which possesses considerable advantages overwhat has been done previously. Of necessity circumferential bands mustbe applied to most installations of this type so as to maintain theinsulating panels in proper position on a tank to be insulated. However,such bands are subjected to great stresses due to expansion of the tankstructure caused by varying elevated temperatures within the tank properand unless provision is made for the ready expansion of such bands thesame are apt to break thus necessitating a replacement of such bands.

It should also be pointed out that he expansion and contraction of ametallic tank structure can easily be calculated when the temperaturesto which the tank is to be exposed are known. Thus, once the amount ofexpansion and contraction of the tank has been determined, the workmenapplying the insulating panels to a structure can easily determine theamount of tension to apply to the clamping members so as to allow suchexpansion and contraction of the band thereby avoiding the breaking offof the band for these reasons.

While I have shown and described the invention as being utilized forinsulating a storage tank of a circular formation, it is obvious thatthe manner of applying insulating panels such as herein described can beequally applied to structure other than cylindrical structures.

From the foregoing, it will be seen that this invention is one walladapted to attain all of the ends and objects hereinabove set forth,together with other advantages which are obvious and which are inherentto the apparatus.

it will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsub-combinations.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in limited sense.

The invention having been described, what is claimed is:

1. A thermally insulated structure comprising a vertically extendingcylindrical tank wall, a plurality of elongated circumferentially spacedvertically extending supports disposed about the outer face of said tankwall, circumferential bands engaging with said supports and preformedinsulating panels disposed between and engaged by said vertical supportsand said circumferential bands, said preformed panels being arranged insuperposed hori zontal rows around said tank wall and provided withbottom edge flanges thereon overlapping the upper edges of the nextvertically underlying row of panels, said vertical supports having slotsformed at the top and bottom ends thereof for the reception of saidoverlapping bottom edge flanges of said panels and said circumferentialbands and spring biased means retaining said bands in tensionedoverlapping relation with said upper edges and bottom edge flanges ofthe superposed rows of panels.

2. The structure recited in claim 1 wherein said circumferential bandwill expand and contract in accordance with the degree of expansion andcontraction occurring in said insulated structure.

3. The structure recited in claim 1 wherein said preformed insulatingpanels comprise a foamed plastic material bonded to a facing sheet.

4. The structure recited in claim 3 wherein said vertical supportsinclude a longitudinally extending center piece with its major planedisposed radially of the tank and having insulation engaging projectionsformed thereon.

5. The structure recited in claim 3 wherein said insulating panelscomprise a facing sheet having a plastic foam secured thereto, saidplastic foam extending flush with the top edge of said sheet whereassaid plastic foam is disposed inwardly of the remaining edges of saidsheet.

6. A thermally insulated structure comprising a cylindrical wall havingall its outer wall surfaces convex, elongated supports disposed aboutthe outer face of said wall parallel to the axis thereof,circumferential bands engaging with said supports and pre-formedinsulating panels disposed between and engaged by said supports and saidcircumferential bands, said pre-formed panels being arranged in rowsaround said wall and provided with edge flanges thereon overlapping theedges of the panels of the next adjacent row, said supports having slotsformed at the ends thereof receiving the overlapping edge flanges ofsaid panels and said circumferentail bands and spring biased meansretaining said bands in tensioned overlapping relation with said edgesand edge flanges of the row of panels.

7. A thermally insulated structure comprising a cylindrical wall havingall its outer wall surfaces convex, elongated circumferentially spacedsupports disposed about the outer face of said wall parallel to the axisthereof, circumferential bands engaging with said supports andpre-formed insulating panels disposed between and engaged by saidsupports and said circumferential bands, said pre-formed panels beingarranged in rows around said wall and provided with edge flanges thereonoverlapping the edges of the panels of the next adjacent row, saidsupports having slots formed at the ends thereof receiving theoverlapping edge flanges of said panels and said circumferential bandsand spring biased means retaining said bands in tensioned overlappingrelation with said edges and edge flanges of the row of panels.

8. The structure recited in claim 6 wherein said circumferential bandwill expand and contract in accordance with the degree of expansion andcontraction occurring in said insulated structure.

9. The structure recited in claim 6 wherein said preformed insulatingpanels comprise a foamed plastic material bonded to a facing sheet.

10. The structure recited in claim 9 wherein su'd insulating panelscomprise a facing sheet having a plastic foam secured thereto, saidplastic foam extending flush 9 with one edge of said sheet wherein saidplastic foam is 2,323,297 7/1943 Collins. disposed inwardly of theremaining edges of said sheet. 2,691,458 10/1954 Dinwiddie 2209 A3,010,599 11/1961 Haines, Jr., et al. 220-9 A References Cited Thefollowing references, cited by the Examiner, are 5 JOSEPH LECLAIRPrimary Examiner of record in the patented file of this patent or theoriginal J. R. GARRETT, Assistant E in r patent.

UNITED STATES PATENTS US. Cl. X.R.

1,675,354 7/1928 Kemper 2 10 52-248, 249; 138-149, 155 1,888,039 11/1932Huff.

